1 /* vi: set sw=4 ts=4: */
3 * Program to load an ELF binary on a linux system, and run it
4 * after resolving ELF shared library symbols
6 * Copyright (C) 2005 by Joakim Tjernlund
7 * Copyright (C) 2000-2006 by Erik Andersen <andersen@codepoet.org>
8 * Copyright (c) 1994-2000 Eric Youngdale, Peter MacDonald,
9 * David Engel, Hongjiu Lu and Mitch D'Souza
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. The name of the above contributors may not be
17 * used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 #include "unsecvars.h"
36 /* Pull in common debug code */
39 #define ALLOW_ZERO_PLTGOT
45 /* Pull in the value of _dl_progname */
46 #include LDSO_ELFINTERP
48 /* Global variables used within the shared library loader */
49 char *_dl_library_path = NULL; /* Where we look for libraries */
50 char *_dl_preload = NULL; /* Things to be loaded before the libs */
51 char *_dl_ldsopath = NULL; /* Location of the shared lib loader */
52 int _dl_errno = 0; /* We can't use the real errno in ldso */
53 size_t _dl_pagesize = 0; /* Store the page size for use later */
54 struct r_debug *_dl_debug_addr = NULL; /* Used to communicate with the gdb debugger */
55 void *(*_dl_malloc_function) (size_t size) = NULL;
56 void (*_dl_free_function) (void *p) = NULL;
58 static int _dl_secure = 1; /* Are we dealing with setuid stuff? */
60 #ifdef __SUPPORT_LD_DEBUG__
61 char *_dl_debug = NULL;
62 char *_dl_debug_symbols = NULL;
63 char *_dl_debug_move = NULL;
64 char *_dl_debug_reloc = NULL;
65 char *_dl_debug_detail = NULL;
66 char *_dl_debug_nofixups = NULL;
67 char *_dl_debug_bindings = NULL;
68 int _dl_debug_file = 2;
71 /* Needed for standalone execution. */
72 unsigned long attribute_hidden _dl_skip_args = 0;
73 const char *_dl_progname = UCLIBC_LDSO; /* The name of the executable being run */
74 #include "dl-startup.c"
75 #include "dl-symbols.c"
79 * This stub function is used by some debuggers. The idea is that they
80 * can set an internal breakpoint on it, so that we are notified when the
81 * address mapping is changed in some way.
83 void _dl_debug_state(void);
84 rtld_hidden_proto(_dl_debug_state, noinline);
85 void _dl_debug_state(void)
87 /* Make sure GCC doesn't recognize this function as pure, to avoid
88 * having the calls optimized away.
92 rtld_hidden_def(_dl_debug_state);
94 static unsigned char *_dl_malloc_addr = NULL; /* Lets _dl_malloc use the already allocated memory page */
95 static unsigned char *_dl_mmap_zero = NULL; /* Also used by _dl_malloc */
97 static struct elf_resolve **init_fini_list;
98 static unsigned int nlist; /* # items in init_fini_list */
99 extern void _start(void);
101 #ifdef __UCLIBC_HAS_SSP__
102 # include <dl-osinfo.h>
103 uintptr_t stack_chk_guard;
104 # ifndef THREAD_SET_STACK_GUARD
105 /* Only exported for architectures that don't store the stack guard canary
106 * in local thread area. */
107 uintptr_t __stack_chk_guard attribute_relro;
108 # ifdef __UCLIBC_HAS_SSP_COMPAT__
109 strong_alias(__stack_chk_guard,__guard)
111 # elif __UCLIBC_HAS_SSP_COMPAT__
112 uintptr_t __guard attribute_relro;
116 char *_dl_getenv(const char *symbol, char **envp)
121 while ((pnt = *envp++)) {
123 while (*pnt && *pnt == *pnt1)
125 if (!*pnt || *pnt != '=' || *pnt1)
132 void _dl_unsetenv(const char *symbol, char **envp)
136 char **newenvp = envp;
138 for (pnt = *envp; pnt; pnt = *++envp) {
140 while (*pnt && *pnt == *pnt1)
142 if (!*pnt || *pnt != '=' || *pnt1)
149 static int _dl_suid_ok(void)
151 __kernel_uid_t uid, euid;
152 __kernel_gid_t gid, egid;
155 euid = _dl_geteuid();
157 egid = _dl_getegid();
159 if (uid == euid && gid == egid) {
165 void *_dl_malloc(size_t size)
170 _dl_debug_early("request for %d bytes\n", size);
173 if (_dl_malloc_function)
174 return (*_dl_malloc_function) (size);
176 if (_dl_malloc_addr - _dl_mmap_zero + size > _dl_pagesize) {
179 /* Since the above assumes we get a full page even if
180 we request less than that, make sure we request a
181 full page, since uClinux may give us less than than
182 a full page. We might round even
183 larger-than-a-page sizes, but we end up never
184 reusing _dl_mmap_zero/_dl_malloc_addr in that case,
187 The actual page size doesn't really matter; as long
188 as we're self-consistent here, we're safe. */
189 if (size < _dl_pagesize)
190 rounded_size = (size + ADDR_ALIGN) & _dl_pagesize;
194 _dl_debug_early("mmapping more memory\n");
195 _dl_mmap_zero = _dl_malloc_addr = _dl_mmap((void *) 0, rounded_size,
196 PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
197 if (_dl_mmap_check_error(_dl_mmap_zero)) {
198 _dl_dprintf(_dl_debug_file, "%s: mmap of a spare page failed!\n", _dl_progname);
202 retval = _dl_malloc_addr;
203 _dl_malloc_addr += size;
206 * Align memory to DL_MALLOC_ALIGN byte boundary. Some
207 * platforms require this, others simply get better
210 _dl_malloc_addr = (unsigned char *) (((unsigned long) _dl_malloc_addr + DL_MALLOC_ALIGN - 1) & ~(DL_MALLOC_ALIGN - 1));
214 static void *_dl_zalloc(size_t size)
216 void *p = _dl_malloc(size);
218 _dl_memset(p, 0, size);
222 void _dl_free(void *p)
224 if (_dl_free_function)
225 (*_dl_free_function) (p);
229 void *_dl_memalign(size_t __boundary, size_t __size)
236 if (_dl_memalign_function)
237 return (*_dl_memalign_function) (__boundary, __size);
239 while (rounded < __boundary) {
240 rounded = (1 << i++);
243 delta = (((size_t) _dl_malloc_addr + __size) & (rounded - 1));
245 if ((result = _dl_malloc(rounded - delta)) == NULL)
248 result = _dl_malloc(__size);
254 static void __attribute__ ((destructor)) __attribute_used__ _dl_fini(void)
257 struct elf_resolve * tpnt;
259 for (i = 0; i < nlist; ++i) {
260 tpnt = init_fini_list[i];
261 if (tpnt->init_flag & FINI_FUNCS_CALLED)
263 tpnt->init_flag |= FINI_FUNCS_CALLED;
264 _dl_run_fini_array(tpnt);
265 if (tpnt->dynamic_info[DT_FINI]) {
266 void (*dl_elf_func) (void);
268 dl_elf_func = (void (*)(void)) (intptr_t) DL_RELOC_ADDR(tpnt->loadaddr, tpnt->dynamic_info[DT_FINI]);
269 _dl_if_debug_dprint("\ncalling FINI: %s\n\n", tpnt->libname);
270 DL_CALL_FUNC_AT_ADDR (dl_elf_func, tpnt->loadaddr, (void(*)(void)));
275 void _dl_get_ready_to_run(struct elf_resolve *tpnt, DL_LOADADDR_TYPE load_addr,
276 ElfW(auxv_t) auxvt[AT_EGID + 1], char **envp,
278 DL_GET_READY_TO_RUN_EXTRA_PARMS)
280 ElfW(Addr) app_mapaddr = 0;
285 int unlazy = 0, trace_loaded_objects = 0;
286 struct dyn_elf *rpnt;
287 struct elf_resolve *tcurr;
288 struct elf_resolve *tpnt1;
289 struct elf_resolve app_tpnt_tmp;
290 struct elf_resolve *app_tpnt = &app_tpnt_tmp;
291 struct r_debug *debug_addr;
293 unsigned long *_dl_envp; /* The environment address */
294 ElfW(Addr) relro_addr = 0;
295 size_t relro_size = 0;
301 /* Wahoo!!! We managed to make a function call! Get malloc
302 * setup so we can use _dl_dprintf() to print debug noise
303 * instead of the SEND_STDERR macros used in dl-startup.c */
305 _dl_memset(app_tpnt, 0, sizeof(*app_tpnt));
307 /* Store the page size for later use */
308 _dl_pagesize = (auxvt[AT_PAGESZ].a_un.a_val) ? (size_t) auxvt[AT_PAGESZ].a_un.a_val : PAGE_SIZE;
309 /* Make it so _dl_malloc can use the page of memory we have already
310 * allocated. We shouldn't need to grab any more memory. This must
311 * be first since things like _dl_dprintf() use _dl_malloc()...
313 _dl_malloc_addr = (unsigned char *)_dl_pagesize;
317 _dl_debug_early("Cool, ldso survived making function calls\n");
319 /* Now we have done the mandatory linking of some things. We are now
320 * free to start using global variables, since these things have all
321 * been fixed up by now. Still no function calls outside of this
322 * library, since the dynamic resolver is not yet ready.
325 _dl_progname = argv[0];
328 if (_start == (void *) auxvt[AT_ENTRY].a_un.a_val) {
329 _dl_dprintf(_dl_debug_file, "Standalone execution is not supported yet\n");
333 /* Start to build the tables of the modules that are required for
334 * this beast to run. We start with the basic executable, and then
335 * go from there. Eventually we will run across ourself, and we
336 * will need to properly deal with that as well.
339 if (_dl_getenv("LD_BIND_NOW", envp))
342 /* Now we need to figure out what kind of options are selected.
343 * Note that for SUID programs we ignore the settings in
346 if ((auxvt[AT_UID].a_un.a_val == (size_t)-1 && _dl_suid_ok()) ||
347 (auxvt[AT_UID].a_un.a_val != (size_t)-1 &&
348 auxvt[AT_UID].a_un.a_val == auxvt[AT_EUID].a_un.a_val &&
349 auxvt[AT_GID].a_un.a_val == auxvt[AT_EGID].a_un.a_val)) {
351 _dl_preload = _dl_getenv("LD_PRELOAD", envp);
352 _dl_library_path = _dl_getenv("LD_LIBRARY_PATH", envp);
354 static const char unsecure_envvars[] =
355 #ifdef EXTRA_UNSECURE_ENVVARS
356 EXTRA_UNSECURE_ENVVARS
362 nextp = unsecure_envvars;
364 _dl_unsetenv (nextp, envp);
365 /* We could use rawmemchr but this need not be fast. */
366 nextp = _dl_strchr(nextp, '\0') + 1;
367 } while (*nextp != '\0');
369 _dl_library_path = NULL;
370 /* SUID binaries can be exploited if they do LAZY relocation. */
375 _dl_error_catch_tsd = &_dl_initial_error_catch_tsd;
376 _dl_init_static_tls = &_dl_nothread_init_static_tls;
379 #ifdef __UCLIBC_HAS_SSP__
380 /* Set up the stack checker's canary. */
381 stack_chk_guard = _dl_setup_stack_chk_guard ();
382 # ifdef THREAD_SET_STACK_GUARD
383 THREAD_SET_STACK_GUARD (stack_chk_guard);
384 # ifdef __UCLIBC_HAS_SSP_COMPAT__
385 __guard = stack_chk_guard;
388 __stack_chk_guard = stack_chk_guard;
392 /* At this point we are now free to examine the user application,
393 * and figure out which libraries are supposed to be called. Until
394 * we have this list, we will not be completely ready for dynamic
398 /* Find the runtime load address of the main executable. This may be
399 * different from what the ELF header says for ET_DYN/PIE executables.
403 ElfW(Phdr) *phdr = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
405 for (idx = 0; idx < auxvt[AT_PHNUM].a_un.a_val; idx++, phdr++)
406 if (phdr->p_type == PT_PHDR) {
407 DL_INIT_LOADADDR_PROG(app_tpnt->loadaddr, auxvt[AT_PHDR].a_un.a_val - phdr->p_vaddr);
411 if (DL_LOADADDR_BASE(app_tpnt->loadaddr))
412 _dl_debug_early("Position Independent Executable: "
413 "app_tpnt->loadaddr=%x\n", DL_LOADADDR_BASE(app_tpnt->loadaddr));
417 * This is used by gdb to locate the chain of shared libraries that are
420 debug_addr = _dl_zalloc(sizeof(struct r_debug));
422 ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
423 for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
424 if (ppnt->p_type == PT_GNU_RELRO) {
425 relro_addr = ppnt->p_vaddr;
426 relro_size = ppnt->p_memsz;
428 if (!app_mapaddr && (ppnt->p_type == PT_LOAD)) {
429 app_mapaddr = DL_RELOC_ADDR (app_tpnt->loadaddr, ppnt->p_vaddr);
431 if (ppnt->p_type == PT_DYNAMIC) {
432 dpnt = (ElfW(Dyn) *) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr);
433 _dl_parse_dynamic_info(dpnt, app_tpnt->dynamic_info, debug_addr, app_tpnt->loadaddr);
434 #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
435 /* Ugly, ugly. We need to call mprotect to change the
436 * protection of the text pages so that we can do the
437 * dynamic linking. We can set the protection back
438 * again once we are done.
440 _dl_debug_early("calling mprotect on the application program\n");
441 /* Now cover the application program. */
442 if (app_tpnt->dynamic_info[DT_TEXTREL]) {
443 ElfW(Phdr) *ppnt_outer = ppnt;
444 ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
445 for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
446 if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
447 _dl_mprotect((void *) (DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr) & PAGE_ALIGN),
448 (DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr) & ADDR_ALIGN) +
449 (unsigned long) ppnt->p_filesz,
450 PROT_READ | PROT_WRITE | PROT_EXEC);
455 if (app_tpnt->dynamic_info[DT_TEXTREL]) {
456 _dl_dprintf(_dl_debug_file, "Can't modify application's text section; use the GCC option -fPIE for position-independent executables.\n");
461 #ifndef ALLOW_ZERO_PLTGOT
462 /* make sure it's really there. */
463 if (app_tpnt->dynamic_info[DT_PLTGOT] == 0)
466 /* OK, we have what we need - slip this one into the list. */
467 app_tpnt = _dl_add_elf_hash_table(_dl_progname, app_tpnt->loadaddr,
468 app_tpnt->dynamic_info,
469 (unsigned long) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr),
471 _dl_loaded_modules->libtype = elf_executable;
472 _dl_loaded_modules->ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
473 _dl_loaded_modules->n_phent = auxvt[AT_PHNUM].a_un.a_val;
474 _dl_symbol_tables = rpnt = _dl_zalloc(sizeof(struct dyn_elf));
475 rpnt->dyn = _dl_loaded_modules;
476 app_tpnt->mapaddr = app_mapaddr;
477 app_tpnt->rtld_flags = unlazy | RTLD_GLOBAL;
478 app_tpnt->usage_count++;
479 app_tpnt->symbol_scope = _dl_symbol_tables;
480 lpnt = (unsigned long *) (app_tpnt->dynamic_info[DT_PLTGOT]);
481 #ifdef ALLOW_ZERO_PLTGOT
484 INIT_GOT(lpnt, _dl_loaded_modules);
487 /* OK, fill this in - we did not have this before */
488 if (ppnt->p_type == PT_INTERP) {
491 tpnt->libname = (char *) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr);
493 /* Store the path where the shared lib loader was found
496 _dl_ldsopath = _dl_strdup(tpnt->libname);
497 ptmp = _dl_strrchr(_dl_ldsopath, '/');
498 if (ptmp != _dl_ldsopath)
501 _dl_debug_early("Lib Loader: (%x) %s\n", (unsigned) DL_LOADADDR_BASE(tpnt->loadaddr), tpnt->libname);
504 /* Discover any TLS sections if the target supports them. */
505 if (ppnt->p_type == PT_TLS) {
507 if (ppnt->p_memsz > 0) {
508 app_tpnt->l_tls_blocksize = ppnt->p_memsz;
509 app_tpnt->l_tls_align = ppnt->p_align;
510 if (ppnt->p_align == 0)
511 app_tpnt->l_tls_firstbyte_offset = 0;
513 app_tpnt->l_tls_firstbyte_offset =
514 (ppnt->p_vaddr & (ppnt->p_align - 1));
515 app_tpnt->l_tls_initimage_size = ppnt->p_filesz;
516 app_tpnt->l_tls_initimage = (void *) ppnt->p_vaddr;
518 /* This image gets the ID one. */
519 _dl_tls_max_dtv_idx = app_tpnt->l_tls_modid = 1;
522 _dl_debug_early("Found TLS header for appplication program\n");
525 _dl_dprintf(_dl_debug_file, "Program uses unsupported TLS data!\n");
530 app_tpnt->relro_addr = relro_addr;
531 app_tpnt->relro_size = relro_size;
535 * Adjust the address of the TLS initialization image in
536 * case the executable is actually an ET_DYN object.
538 if (app_tpnt->l_tls_initimage != NULL) {
539 app_tpnt->l_tls_initimage =
540 (char *) app_tpnt->l_tls_initimage + app_tpnt->loadaddr;
541 _dl_debug_early("Relocated TLS initial image from %x to %x (size = %x)\n",
542 (unsigned int)app_tpnt->l_tls_initimage,
543 app_tpnt->l_tls_initimage, app_tpnt->l_tls_initimage_size);
547 #ifdef __SUPPORT_LD_DEBUG__
548 _dl_debug = _dl_getenv("LD_DEBUG", envp);
550 if (_dl_strstr(_dl_debug, "all")) {
551 _dl_debug_detail = _dl_debug_move = _dl_debug_symbols
552 = _dl_debug_reloc = _dl_debug_bindings = _dl_debug_nofixups = (void*)1;
554 _dl_debug_detail = _dl_strstr(_dl_debug, "detail");
555 _dl_debug_move = _dl_strstr(_dl_debug, "move");
556 _dl_debug_symbols = _dl_strstr(_dl_debug, "sym");
557 _dl_debug_reloc = _dl_strstr(_dl_debug, "reloc");
558 _dl_debug_nofixups = _dl_strstr(_dl_debug, "nofix");
559 _dl_debug_bindings = _dl_strstr(_dl_debug, "bind");
564 const char *dl_debug_output;
566 dl_debug_output = _dl_getenv("LD_DEBUG_OUTPUT", envp);
568 if (dl_debug_output) {
569 char tmp[22], *tmp1, *filename;
572 _dl_memset(tmp, 0, sizeof(tmp));
573 tmp1 = _dl_simple_ltoa( tmp, (unsigned long)_dl_getpid());
575 len1 = _dl_strlen(dl_debug_output);
576 len2 = _dl_strlen(tmp1);
578 filename = _dl_malloc(len1 + len2 + 2);
581 _dl_strcpy (filename, dl_debug_output);
582 filename[len1] = '.';
583 _dl_strcpy (&filename[len1+1], tmp1);
585 _dl_debug_file = _dl_open(filename, O_WRONLY|O_CREAT, 0644);
586 if (_dl_debug_file < 0) {
588 _dl_dprintf(_dl_debug_file, "can't open file: '%s'\n",filename);
595 if (_dl_getenv("LD_TRACE_LOADED_OBJECTS", envp) != NULL) {
596 trace_loaded_objects++;
599 #ifndef __LDSO_LDD_SUPPORT__
600 if (trace_loaded_objects) {
601 _dl_dprintf(_dl_debug_file, "Use the ldd provided by uClibc\n");
607 * OK, fix one more thing - set up debug_addr so it will point
608 * to our chain. Later we may need to fill in more fields, but this
609 * should be enough for now.
611 debug_addr->r_map = (struct link_map *) _dl_loaded_modules;
612 debug_addr->r_version = 1;
613 debug_addr->r_ldbase = (ElfW(Addr)) DL_LOADADDR_BASE(load_addr);
614 debug_addr->r_brk = (unsigned long) &_dl_debug_state;
615 _dl_debug_addr = debug_addr;
617 /* Do not notify the debugger until the interpreter is in the list */
619 /* OK, we now have the application in the list, and we have some
620 * basic stuff in place. Now search through the list for other shared
621 * libraries that should be loaded, and insert them on the list in the
631 while (*str == ':' || *str == ' ' || *str == '\t')
636 while (*str2 && *str2 != ':' && *str2 != ' ' && *str2 != '\t')
641 if (!_dl_secure || _dl_strchr(str, '/') == NULL) {
642 _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", str, _dl_progname);
644 tpnt1 = _dl_load_shared_library(_dl_secure, &rpnt, NULL, str, trace_loaded_objects);
646 #ifdef __LDSO_LDD_SUPPORT__
647 if (trace_loaded_objects)
648 _dl_dprintf(1, "\t%s => not found\n", str);
652 _dl_dprintf(_dl_debug_file, "%s: can't load " "library '%s'\n", _dl_progname, str);
656 tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
658 _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
660 #ifdef __LDSO_LDD_SUPPORT__
661 if (trace_loaded_objects &&
662 tpnt1->usage_count == 1) {
663 /* This is a real hack to make
664 * ldd not print the library
665 * itself when run on a
668 if (_dl_strcmp(_dl_progname, str) != 0)
669 _dl_dprintf(1, "\t%s => %s (%x)\n", str, tpnt1->libname,
670 DL_LOADADDR_BASE(tpnt1->loadaddr));
678 while (*str == ':' || *str == ' ' || *str == '\t')
683 #ifdef __LDSO_PRELOAD_FILE_SUPPORT__
690 if (_dl_stat(LDSO_PRELOAD, &st) || st.st_size == 0) {
694 if ((fd = _dl_open(LDSO_PRELOAD, O_RDONLY, 0)) < 0) {
695 _dl_dprintf(_dl_debug_file, "%s: can't open file '%s'\n",
696 _dl_progname, LDSO_PRELOAD);
700 preload = (caddr_t) _dl_mmap(0, st.st_size + 1,
701 PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
703 if (preload == (caddr_t) -1) {
704 _dl_dprintf(_dl_debug_file, "%s:%i: can't map '%s'\n",
705 _dl_progname, __LINE__, LDSO_PRELOAD);
709 /* convert all separators and comments to spaces */
710 for (cp = preload; *cp; /*nada */ ) {
711 if (*cp == ':' || *cp == '\t' || *cp == '\n') {
713 } else if (*cp == '#') {
716 } while (*cp != '\n' && *cp != '\0');
722 /* find start of first library */
723 for (cp = preload; *cp && *cp == ' '; cp++)
727 /* find end of library */
728 for (cp2 = cp; *cp && *cp != ' '; cp++)
733 _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", cp2, _dl_progname);
735 tpnt1 = _dl_load_shared_library(0, &rpnt, NULL, cp2, trace_loaded_objects);
737 #ifdef __LDSO_LDD_SUPPORT__
738 if (trace_loaded_objects)
739 _dl_dprintf(1, "\t%s => not found\n", cp2);
743 _dl_dprintf(_dl_debug_file, "%s: can't load library '%s'\n", _dl_progname, cp2);
747 tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
749 _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
751 #ifdef __LDSO_LDD_SUPPORT__
752 if (trace_loaded_objects &&
753 tpnt1->usage_count == 1) {
754 _dl_dprintf(1, "\t%s => %s (%x)\n",
756 DL_LOADADDR_BASE(tpnt1->loadaddr));
761 /* find start of next library */
763 for ( /*nada */ ; *cp && *cp == ' '; cp++)
767 _dl_munmap(preload, st.st_size + 1);
769 #endif /* __LDSO_PRELOAD_FILE_SUPPORT__ */
772 for (tcurr = _dl_loaded_modules; tcurr; tcurr = tcurr->next) {
773 ElfW(Dyn) *this_dpnt;
776 for (this_dpnt = (ElfW(Dyn) *) tcurr->dynamic_addr; this_dpnt->d_tag; this_dpnt++) {
777 if (this_dpnt->d_tag == DT_NEEDED) {
779 struct init_fini_list *tmp;
781 lpntstr = (char*) (tcurr->dynamic_info[DT_STRTAB] + this_dpnt->d_un.d_val);
782 name = _dl_get_last_path_component(lpntstr);
783 if (_dl_strcmp(name, UCLIBC_LDSO) == 0)
786 _dl_if_debug_dprint("\tfile='%s'; needed by '%s'\n", lpntstr, _dl_progname);
788 if (!(tpnt1 = _dl_load_shared_library(0, &rpnt, tcurr, lpntstr, trace_loaded_objects))) {
789 #ifdef __LDSO_LDD_SUPPORT__
790 if (trace_loaded_objects) {
791 _dl_dprintf(1, "\t%s => not found\n", lpntstr);
796 _dl_dprintf(_dl_debug_file, "%s: can't load library '%s'\n", _dl_progname, lpntstr);
801 tmp = alloca(sizeof(struct init_fini_list)); /* Allocates on stack, no need to free this memory */
803 tmp->next = tcurr->init_fini;
804 tcurr->init_fini = tmp;
806 tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
808 _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
810 #ifdef __LDSO_LDD_SUPPORT__
811 if (trace_loaded_objects &&
812 tpnt1->usage_count == 1) {
813 _dl_dprintf(1, "\t%s => %s (%x)\n",
814 lpntstr, tpnt1->libname,
815 DL_LOADADDR_BASE(tpnt1->loadaddr));
823 --nlist; /* Exclude the application. */
824 init_fini_list = _dl_malloc(nlist * sizeof(struct elf_resolve *));
826 for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
827 init_fini_list[i++] = tcurr;
830 /* Sort the INIT/FINI list in dependency order. */
831 for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
834 for (j = 0; init_fini_list[j] != tcurr; ++j)
836 for (k = j + 1; k < nlist; ++k) {
837 struct init_fini_list *runp = init_fini_list[k]->init_fini;
839 for (; runp; runp = runp->next) {
840 if (runp->tpnt == tcurr) {
841 struct elf_resolve *here = init_fini_list[k];
842 _dl_if_debug_dprint("Move %s from pos %d to %d in INIT/FINI list\n", here->libname, k, j);
843 for (i = (k - j); i; --i)
844 init_fini_list[i+j] = init_fini_list[i+j-1];
845 init_fini_list[j] = here;
852 #ifdef __SUPPORT_LD_DEBUG__
854 _dl_dprintf(_dl_debug_file, "\nINIT/FINI order and dependencies:\n");
855 for (i = 0; i < nlist; i++) {
856 struct init_fini_list *tmp;
858 _dl_dprintf(_dl_debug_file, "lib: %s has deps:\n",
859 init_fini_list[i]->libname);
860 tmp = init_fini_list[i]->init_fini;
861 for (; tmp; tmp = tmp->next)
862 _dl_dprintf(_dl_debug_file, " %s ", tmp->tpnt->libname);
863 _dl_dprintf(_dl_debug_file, "\n");
869 * If the program interpreter is not in the module chain, add it.
870 * This will be required for dlopen to be able to access the internal
871 * functions in the dynamic linker and to relocate the interpreter
872 * again once all libs are loaded.
875 ElfW(Ehdr) *epnt = (ElfW(Ehdr) *) auxvt[AT_BASE].a_un.a_val;
876 ElfW(Phdr) *myppnt = (ElfW(Phdr) *) DL_RELOC_ADDR(load_addr, epnt->e_phoff);
879 tpnt = _dl_add_elf_hash_table(tpnt->libname, load_addr,
881 (unsigned long)tpnt->dynamic_addr,
884 if (_dl_stat(tpnt->libname, &st) >= 0) {
885 tpnt->st_dev = st.st_dev;
886 tpnt->st_ino = st.st_ino;
888 tpnt->n_phent = epnt->e_phnum;
890 for (j = 0; j < epnt->e_phnum; j++, myppnt++) {
891 if (myppnt->p_type == PT_GNU_RELRO) {
892 tpnt->relro_addr = myppnt->p_vaddr;
893 tpnt->relro_size = myppnt->p_memsz;
897 tpnt->libtype = program_interpreter;
899 tpnt->symbol_scope = _dl_symbol_tables;
901 rpnt->next = _dl_zalloc(sizeof(struct dyn_elf));
902 rpnt->next->prev = rpnt;
905 rpnt = _dl_zalloc(sizeof(struct dyn_elf));
908 tpnt->rtld_flags = RTLD_NOW | RTLD_GLOBAL; /* Must not be LAZY */
909 #ifdef RERELOCATE_LDSO
910 /* Only rerelocate functions for now. */
911 tpnt->init_flag = RELOCS_DONE;
912 lpnt = (unsigned long *) (tpnt->dynamic_info[DT_PLTGOT]);
913 # ifdef ALLOW_ZERO_PLTGOT
914 if (tpnt->dynamic_info[DT_PLTGOT])
916 INIT_GOT(lpnt, tpnt);
918 tpnt->init_flag = RELOCS_DONE | JMP_RELOCS_DONE;
923 #ifdef __LDSO_LDD_SUPPORT__
924 /* End of the line for ldd.... */
925 if (trace_loaded_objects) {
926 _dl_dprintf(1, "\t%s => %s (%x)\n",
927 rpnt->dyn->libname + _dl_strlen(_dl_ldsopath) + 1,
928 rpnt->dyn->libname, DL_LOADADDR_BASE(rpnt->dyn->loadaddr));
934 /* We do not initialize any of the TLS functionality unless any of the
935 * initial modules uses TLS. This makes dynamic loading of modules with
936 * TLS impossible, but to support it requires either eagerly doing setup
937 * now or lazily doing it later. Doing it now makes us incompatible with
938 * an old kernel that can't perform TLS_INIT_TP, even if no TLS is ever
939 * used. Trying to do it lazily is too hairy to try when there could be
940 * multiple threads (from a non-TLS-using libpthread). */
941 bool was_tls_init_tp_called = tls_init_tp_called;
943 _dl_debug_early("Calling init_tls()!\n");
948 _dl_debug_early("Beginning relocation fixups\n");
952 * Relocation of the GOT entries for MIPS have to be done
953 * after all the libraries have been loaded.
955 _dl_perform_mips_global_got_relocations(_dl_loaded_modules, !unlazy);
959 * OK, now all of the kids are tucked into bed in their proper
960 * addresses. Now we go through and look for REL and RELA records that
961 * indicate fixups to the GOT tables. We need to do this in reverse
962 * order so that COPY directives work correctly.
964 if (_dl_symbol_tables)
965 if (_dl_fixup(_dl_symbol_tables, unlazy))
968 for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
969 if (tpnt->relro_size)
970 _dl_protect_relro (tpnt);
974 if (!was_tls_init_tp_called && _dl_tls_max_dtv_idx > 0)
975 ++_dl_tls_generation;
977 _dl_debug_early("Calling _dl_allocate_tls_init()!\n");
979 /* Now that we have completed relocation, the initializer data
980 for the TLS blocks has its final values and we can copy them
981 into the main thread's TLS area, which we allocated above. */
982 _dl_allocate_tls_init (tcbp);
984 /* And finally install it for the main thread. If ld.so itself uses
985 TLS we know the thread pointer was initialized earlier. */
986 if (! tls_init_tp_called) {
987 const char *lossage = (char *) TLS_INIT_TP (tcbp, USE___THREAD);
988 if (__builtin_expect (lossage != NULL, 0)) {
989 _dl_debug_early("cannot set up thread-local storage: %s\n", lossage);
995 /* OK, at this point things are pretty much ready to run. Now we need
996 * to touch up a few items that are required, and then we can let the
997 * user application have at it. Note that the dynamic linker itself
998 * is not guaranteed to be fully dynamicly linked if we are using
999 * ld.so.1, so we have to look up each symbol individually.
1002 _dl_envp = (unsigned long *) (intptr_t) _dl_find_hash(__C_SYMBOL_PREFIX__ "__environ", _dl_symbol_tables, NULL, 0, NULL);
1004 *_dl_envp = (unsigned long) envp;
1006 #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
1011 /* We had to set the protections of all pages to R/W for
1012 * dynamic linking. Set text pages back to R/O.
1014 for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
1015 for (myppnt = tpnt->ppnt, j = 0; j < tpnt->n_phent; j++, myppnt++) {
1016 if (myppnt->p_type == PT_LOAD && !(myppnt->p_flags & PF_W) && tpnt->dynamic_info[DT_TEXTREL]) {
1017 _dl_mprotect((void *) (DL_RELOC_ADDR(tpnt->loadaddr, myppnt->p_vaddr) & PAGE_ALIGN),
1018 (myppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) myppnt->p_filesz, LXFLAGS(myppnt->p_flags));
1025 /* Notify the debugger we have added some objects. */
1026 _dl_debug_addr->r_state = RT_ADD;
1029 /* Run pre-initialization functions for the executable. */
1030 _dl_run_array_forward(_dl_loaded_modules->dynamic_info[DT_PREINIT_ARRAY],
1031 _dl_loaded_modules->dynamic_info[DT_PREINIT_ARRAYSZ],
1032 _dl_loaded_modules->loadaddr);
1034 /* Run initialization functions for loaded objects. For the
1035 main executable, they will be run from __uClibc_main. */
1036 for (i = nlist; i; --i) {
1037 tpnt = init_fini_list[i-1];
1038 tpnt->init_fini = NULL; /* Clear, since alloca was used */
1039 if (tpnt->init_flag & INIT_FUNCS_CALLED)
1041 tpnt->init_flag |= INIT_FUNCS_CALLED;
1043 if (tpnt->dynamic_info[DT_INIT]) {
1044 void (*dl_elf_func) (void);
1046 dl_elf_func = (void (*)(void)) DL_RELOC_ADDR(tpnt->loadaddr, tpnt->dynamic_info[DT_INIT]);
1048 _dl_if_debug_dprint("calling INIT: %s\n\n", tpnt->libname);
1050 DL_CALL_FUNC_AT_ADDR (dl_elf_func, tpnt->loadaddr, (void(*)(void)));
1053 _dl_run_init_array(tpnt);
1056 /* Find the real malloc function and make ldso functions use that from now on */
1057 _dl_malloc_function = (void* (*)(size_t)) (intptr_t) _dl_find_hash(__C_SYMBOL_PREFIX__ "malloc",
1058 _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT, NULL);
1061 /* Find the real functions and make ldso functions use them from now on */
1062 _dl_calloc_function = (void* (*)(size_t, size_t)) (intptr_t)
1063 _dl_find_hash(__C_SYMBOL_PREFIX__ "calloc", _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT, NULL);
1065 _dl_realloc_function = (void* (*)(void *, size_t)) (intptr_t)
1066 _dl_find_hash(__C_SYMBOL_PREFIX__ "realloc", _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT, NULL);
1068 _dl_free_function = (void (*)(void *)) (intptr_t)
1069 _dl_find_hash(__C_SYMBOL_PREFIX__ "free", _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT, NULL);
1071 _dl_memalign_function = (void* (*)(size_t, size_t)) (intptr_t)
1072 _dl_find_hash(__C_SYMBOL_PREFIX__ "memalign", _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT, NULL);
1076 /* Notify the debugger that all objects are now mapped in. */
1077 _dl_debug_addr->r_state = RT_CONSISTENT;
1081 #include "dl-hash.c"